Minimally invasive surgical needle and cauterizing assembly and methods

ABSTRACT

A minimally invasive surgical assembly broadly includes an outer hollow needle which has an outer diameter, a longitudinal axis, and a sharp distal end. An insulating member extends through the hollow needle and is movable relative to the hollow needle. An elongated member extends through the insulating member and is movable relative to both the insulating member and the hollow needle. A resilient wire projects from the elongated member and is retractable within and extendable outside of the insulating member and the hollow needle. The insulating member, elongated member, and resilient wire are movable relative to the needle using first and second moving means whereby the surgical assembly assumes various configurations having different operational functions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 12/100,185, filed on Apr. 9, 2008, the disclosureof each of which is incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates broadly to surgical instruments and methods oftheir use. More particularly, this invention relates to a minimallyinvasive surgical assembly that incorporates both a needle and acauterizing device that is extendible through and beyond the needle andretractable into the needle. The invention has particular application tolaparoscopic-type surgery, although it is not limited thereto.

2. State of the Art

Over the last two decades, minimally invasive surgery has become thestandard for many types of surgeries which were previously accomplishedthrough open surgery. Minimally invasive surgery generally involvesintroducing an optical element (e.g., laparoscope or endoscope) througha surgical or natural port in the body, advancing one or more surgicalinstruments through additional ports or through the endoscope,conducting the surgery with the surgical instruments, and withdrawingthe instruments and scope from the body. In laparoscopic surgery(broadly defined herein to be any surgery where a port is made via asurgical incision, including but not limited to abdominal laparoscopy,arthroscopy, spinal laparoscopy, etc.), a port for a scope is typicallymade using a surgical trocar assembly. The trocar assembly oftenincludes a port, a sharp pointed element (trocar) extending through andbeyond the distal end of the port, and at least in the case of abdominallaparoscopy, a valve on the proximal portion of the port. Typically, asmall incision is made in the skin at a desired location in the patient.The trocar assembly, with the trocar extending out of the port, is thenforced through the incision, thereby widening the incision andpermitting the port to extend through the incision, past any facie, andinto the body (cavity). The trocar is then withdrawn, leaving the portin place. In certain circumstances, an insufflation element may beattached to the trocar port in order to insufflate the surgical site. Anoptical element may then be introduced through the trocar port.Additional ports are then typically made so that additional laparoscopicinstruments may be introduced into the body.

Trocar assemblies are manufactured in different sizes. Typical trocarport sizes include 5 mm, 10 mm and 12 mm (available from companies suchas Taut and U.S. Surgical), which are sized to permit variously sizedlaparoscopic instruments to be introduced therethrough including, e.g.,graspers, dissectors, staplers, scissors, suction/irrigators, clamps,forceps, biopsy forceps, etc. Laparoscopic surgery has reduced thetrauma associated with various surgical procedures and has concomitantlyreduced recovery time from these surgeries. The 5 mm trocar ports fromthe various instruments used in laparoscopic surgery leave a pluralityof holes that must be stitched, which typically result in scars.

One surgical instrument often used during laparoscopic surgery is acauterization tool. Cauterization (cautery) tools are employed forstopping internal bleeding by cauterizing areas inside the body thathave been pierced or opened during surgery, and for cutting throughtissue inside of the body in order to destroy and/or remove it. Thecautery tool is typically electrified to destroy the tissue. The cauterydevice may be electrified at different voltages to achieve differentfunctions. At lower voltages, continuous alternating current quicklyproduces heat that vaporizes tissue at the tip of the cautery tool. Athigher voltages, heat is produced more slowly, which causes morewidespread tissue damage near the tip of the cautery tool. The lattereffect causes blood near the site to coagulate. The process of usingelectricity to destroy tissue is called “electrocauterization.”

Electrocauterization is performed in either a monopolar or bipolar mode.In monopolar electrocauterization, a patient's body serves as theground, and current passes from the cautery device to the patient. Inbipolar electrocauterization, the cautery device contains sending andreceiving electrodes that are placed around tissue. The current passesbetween the electrodes and cauterizes the tissue therebetween.

A common cautery device used in monopolar electrocauterization is ascalpel-shaped spatula, which may serve as both a coagulator and anelectric scalpel. A surgeon operates the cautery device by pushing abutton on its shaft and/or by depressing a foot pedal, thereby allowingcurrent to flow through the cautery device.

A number of cautery and needle combinations are known in the art. U.S.Pat. No. 5,578,030 discloses a biopsy needle that procures a tissuespecimen and cauterizes the resulting wound, which minimizes bleedingand helps prevent the proliferation of cancer cells along the path ofthe needle. The device has a sharp cutting edge disposed at a junctionbetween a front wall and a top surface, a configuration that enablestissue to be cut and forced into the biopsy needle as the biopsy needleis retracted from a patient. A conductor applies electrical current tothe needle, which heats it and cauterizes the wound resulting from theexcision of the tissue specimen.

U.S. Pat. No. 5,342,357 discloses an electrosurgical probe that cuts andcauterizes tissue. The device is adapted to accommodate fluid flowthrough an outlet port to surrounding tissue so as to limit heattransfer from the device thereto, thereby preventing the surroundingtissue from sticking to the device.

U.S. Pat. No. 5,906,620 discloses a surgical instrument assembly thatincludes a cauterization snare and a suture member, both of which aredisposed in a first tubular sheath. The suture member is also disposedin a second tubular sheath that facilitates the release and positioningof the suture member around a selected body of tissue. The secondtubular sheath is movably disposed in the first tubular sheath andcontains a tensioning means extending through the second tubular sheathfor tightening the suture member. The device is used to remove a polypor other body tissue.

SUMMARY OF THE INVENTION

A minimally invasive surgical assembly is provided. The surgicalassembly according to the invention broadly includes an outer hollowneedle having a longitudinal axis and a sharp distal end for piercingtissue, an insulating member extending coaxially through and movablerelative to the hollow needle, an elongated member extending coaxiallythrough and movable relative to the insulating member and the hollowneedle, a resilient wire attached to and projecting outward from adistal end of the elongated member to a cauterization tip, and aproximal assembly for moving the insulating and elongated members tovarious positions relative to the needle and to each other. A housingmounted to the outer surface of the needle encapsulates and protects theproximal assembly, functions as a secondary handle or grip for anoperator holding the surgical assembly, and preferably provides airtight seals at the proximal end of the needle while allowing theinsulating and elongated members, which extend into the housing, to moverelative thereto. By moving the insulating and elongated membersrelative to each other and relative to the needle, variousconfigurations are obtained, each of which has its own benefits and/oroperational functions.

In the preferred embodiment, the proximal assembly includes a firstmechanism for causing the elongated member to move relative to both theneedle and the insulating member, and a second mechanism for moving theinsulating member relative to the needle. The first mechanism of theproximal assembly is a plunger and a handle or finger loop. The plungeron one end is mounted to the proximal end of the elongated member and onthe other is affixed to the handle. The plunger is movable along thelongitudinal axis of the needle and drives the elongated member and theresilient wire to various positions relative to the sharp distal end ofthe needle.

The second mechanism of the proximal assembly includes a cage mounted tothe proximal end of the insulating member, and a spring mounted at aproximal end to a portion of the housing. The spring preferably wrapsaround the cage and biases the cage toward a distal position. Proximalmovement of the cage and attached insulating member is achieved when theplunger engages the cage and is moved in a proximal direction. Distalmovement of the cage and attached insulating member is achieved by thebias of the spring when the plunger is moved in a distal direction. Thehousing of the surgical assembly limits the distal displacement of thecage. Thus, the bias of the spring moves the cage in a distal directionas the plunger is moved in a distal direction until the cage is stoppedby the housing. At that point, the plunger decouples from the cage andis further movable in a distal direction. These first and secondmechanisms allow the surgical assembly to achieve various functionalconfigurations from a relatively simple linear motion of the plunger.

In the preferred embodiment, the surgical assembly includes a fixingmeans for fixing the surgical assembly in first, second, third, andfourth configurations. In the first configuration, the distal end of theinsulating member and the cauterizing tip of the resilient wire aredisposed inside the needle such that the sharp distal end of the needleis exposed and ready for insertion into a patient. In the secondconfiguration, the distal end of the insulating member is disposedbeyond the sharp distal end of the needle, which protects and insulatesthe sharp distal end, and the cauterizing tip of the resilient wire isdisposed inside the insulating member, which electrically insulates thecauterizing tip and allows the surgical assembly to be maneuvered withinthe patient without cutting or cauterizing any tissue. In the thirdconfiguration, the distal end of the insulating member is disposedbeyond the sharp distal end of the needle, and the cauterizing tip isdisposed just beyond the distal end of the insulating member. Thisconfiguration allows for electrical activation and operation of thecauterizing tip while insulating the sharp distal end of the needle. Inthe fourth configuration, the distal end of the insulating member isdisposed beyond the sharp distal end of the needle, and the resilientwire is fully extended and bent such that the cauterization tip isoffset from the longitudinal axis of the needle by a distance at leastas large as one half of the outer diameter of the needle, and preferablyby a distance exceeding twice the diameter of the needle. Thisconfiguration allows for electrical activation and operation of thecauterizing tip at a location outside of the cylindrical projection ofthe hollow needle, thereby increasing the area within the patient that asurgeon can reach after inserting the surgical assembly at a specificlocation through a small incision.

The surgical assembly may be used during laparoscopic surgery instead ofusing an extra trocar and laparoscopic instrument. In particular, withthe insulating member, the elongated member, and the attached resilientwire with the cauterization tip all disposed inside the needle, theneedle is used to puncture the skin, and is advanced into the body(e.g., the abdomen). At a desired location (typically under guidance ofan already inserted scope), the movement of the needle is stopped. Theplunger is then distally advanced relative to the needle, which distallyadvances the insulating member relative to the needle until the distalend of the insulating member extends past the sharp distal end of theneedle. This configuration insulates the needle and acts as a barrier toprevent injury or trauma to the patient in the event that the needle isinadvertently further inserted. With the needle now in a relativelyfixed position, the plunger is further distally advanced relative to theneedle, which distally advances the elongated member and resilient wirerelative to both the needle and the insulating member. In a first distalposition, the cauterizing tip of the resilient wire extends just beyondthe distal end of the insulating member, is in-line with thelongitudinal axis of the needle, and may be used as a cautery device inthat capacity. As the elongated member is moved further distally beyondthe first distal position, the cauterizing tip of the resilient wire, asit is advanced beyond the distal ends of the needle and insulatingmember, automatically moves transverse to the longitudinal axis of theneedle. In a second distal (fully extended) position, the bias of theresilient wire toward the bent configuration has caused the resilientwire to bend enough to dispose the cauterizing tip of the resilient wireat an offset location relative to the longitudinal axis of the needle.

Preferably, the cauterizing tip of the resilient wire is electrifiedonce it extends beyond the distal ends of the insulating member andneedle. The surgical assembly may then be used as a cauterizing device.At any time, the resilient wire and elongated member may be retractedwithin the needle by proximally moving the plunger relative to theneedle. The surgical assembly can then be pulled out of the body,leaving only a small puncture mark which will often heal withoutstitching and a scar.

Objects and advantages of the invention will become apparent to thoseskilled in the art upon reference to the detailed description taken inconjunction with the provided figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is perspective view of a preferred embodiment of the surgicalassembly of the invention with the cauterizing tip of the surgicalinstrument in an extended position.

FIG. 2A is a broken perspective view of the distal end of the needle ofthe surgical assembly of FIG. 1 in a first configuration.

FIG. 2B is a broken perspective view of the distal end of the needle andinsulating member of the surgical assembly of FIG. 1 in a secondconfiguration.

FIG. 2C is a broken perspective view of the distal end of the needle,insulating member, and resilient wire of the surgical assembly of FIG. 1in a third configuration.

FIG. 2D is a broken perspective view of the distal end of the needle,insulating member, elongated member, and resilient wire of the surgicalassembly of FIG. 1 in a fourth configuration.

FIG. 3A is a broken longitudinal sectional view of the surgical assemblyof FIG. 1 in a first configuration.

FIG. 3B is a broken longitudinal sectional view of the surgical assemblyof FIG. 1 in a second configuration.

FIG. 3C is a broken longitudinal sectional view of the surgical assemblyof FIG. 1 in a third configuration.

FIG. 3D is a broken longitudinal sectional view of the surgical assemblyof FIG. 1 in a fourth configuration.

FIG. 4 is a broken partial cutaway perspective view of the proximal endof the surgical assembly in the configuration of FIG. 3D with theplunger removed.

FIG. 5 is an enlarged view of the plunger of the surgical assembly ofFIGS. 3A-3D.

FIG. 6 is the view of FIG. 4 with the plunger of the surgical assemblyin place.

FIG. 7 is a broken cross sectional view of the plunger and cage of thesurgical assembly in the configuration of FIG. 3D.

FIG. 8 is an enlarged view of the electrical clip of the surgicalassembly of FIG. 4.

FIG. 9 is an enlarged side perspective view of the resilient wire of thesurgical assembly of FIG. 1.

FIG. 10 is an enlarged front perspective view of the resilient wire ofthe surgical assembly of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A minimally invasive surgical assembly 10 according to the invention andas seen in FIGS. 1-5 broadly includes an outer hollow needle 12, aninsulating member 14 extending coaxially through the needle 12, anelongated member 16 (FIGS. 2D, 4) extending coaxially through theinsulating member 14 and the needle 12 which terminates in a resilientwire 18, and a proximal assembly 19 for coaxially moving the insulatingand elongated members 14, 16 to various positions relative to the needle12 and to each other. A housing 21 mounted to the outer surface of theneedle 12 encapsulates and protects the proximal assembly 19, functionsas a secondary handle or grip for an operator holding the surgicalassembly 10, and accommodates the relative movement of the insulatingmember 14 and elongated member 16 relative to the needle 12 and to eachother while preferably maintaining a sealed, air tight environment.Various configurations of the surgical assembly 10, each havingdifferent benefits and/or functional operations, are achieved by movingthe insulating and elongated members 14, 16 relative to the needle 12and to each other as described hereinafter.

The needle 12 has a proximal end 12 a (FIG. 4), a sharp distal end 12 b,and a longitudinal axis 12 c (FIGS. 2A-2D). The preferred needle 12 ofthe invention has an outer diameter of 2.2 mm (0.087 inches).+−0.20% andis angled at the sharp distal end 12 b at about 35.degree. relative tothe longitudinal axis 12 c of the needle 12 for piercing through tissue.The needle 12 preferably has an inside diameter of 1.7 mm (0.067inches), a wall thickness of 0.25 mm (0.01 inch), is typically between10 and 30 cm long, and more typically between 13 and 18 cm long(although other sizes could be used, depending upon the surgeryinvolved, and typically larger for obese patients and smaller forinfants and small children), and is preferably made from stainlesssteel, although other materials could be utilized. The needle 12preferably has an outer layer of insulation 15 (FIGS. 2A-2D). Insulation15 is preferably a shrink wrap layer having a very high dielectricstrength, e.g., greater than 4,000 V/mil, which prevents electricaldischarge passing through the needle 12 and insulates the needle 12 frombeing charged when the surgical assembly 10 is used as a cauterizationdevice as further discussed below.

The insulating member 14 of the surgical assembly 10 has a proximal end14 a (FIGS. 3A-3D) and a distal end 14 b (FIGS. 2B-2D), extendscoaxially through the needle 12, and is movable relative thereto. Theinsulating member 14 is preferably made from material such as polyimidetubing having a very high dielectric strength, e.g., greater than 4,000V/mil. Insulating member 14 preferably has a wall thickness of at least0.001 inches, and more preferably is approximately 0.005-0.012 inchesthick, and most preferably 0.009 inches thick. Insulating member 14 hasan outer diameter of approximately 0.065 inches.

The elongated member 16 has a proximal end 16 a (FIG. 4), a distal end16 b (FIG. 2D), extends coaxially through the insulating member 14 andthe needle 12, and is movable relative to both the insulating member 14and the needle 12. The elongated member 16 is preferably formed fromstainless steel in the shape of an elongated rod, although othermaterials and shapes could be utilized. The elongated member 16 ispreferably about 0.03-0.04 inches in diameter.

As seen in FIG. 2D, the resilient wire 18 has a proximal end 18 a and adistal cauterizing tip 18 b. The resilient wire 18 is preferably madefrom 17-7 heat treated stainless steel, is 0.012 inches thick, 1.2inches long, 0.045 inches wide, and effectively presents as a flatcurved spatula (FIG. 10). The flattened resilient wire 18 is retractablewithin both the insulating member 14 and the hollow needle 12, and thecauterizing tip 18 b of the resilient wire 18 is extendable beyonddistal ends 12 b, 14 b, of the hollow needle 12 and the insulatingmember 14. The resilient wire 18 is biased toward a bent configuration(as shown in FIGS. 1, 2D, and 9) such that, when extended beyond thedistal ends 12 b, 14 b of the hollow needle 12 and the insulating member14, the cauterizing tip 18 b automatically bends relative to thelongitudinal axis 12 c of the hollow needle 18. The proximal end 18 a ofthe resilient wire 18 may be welded to the distal end 16 b of theelongated member 16, or attached to the elongated member 16 in any otherdesired manner known in the art. All but the distal ¼ inch of theresilient wire 18 is coated with an insulation 17 (FIGS. 2D, 9). Asfurther discussed below, the resilient wire 18 of the surgical assembly10 operates as an extendable and retractable cauterization tool withinthe hollow needle 10, and the relative locations of the needle 12,insulating member 15, elongated member 16, and resilient wire 18 givevarious functional benefits to the surgical assembly 10.

The housing 21 is mounted to the outer surface of the needle 12 andencapsulates and protects the proximal assembly 19. The housing 21 ispreferably similar to the proximal housing that is described in commonlyowned U.S. patent application Ser. No. 11/685,522 (referred to thereinas the handle 520), which is herein incorporated by reference in itsentirety. The needle 12 has a hub 13 (FIGS. 3A-3D) which is trapped in adistal portion 23 (FIGS. 3A-3D, 4, and 6) of the housing 21. The housing21 should be made from a non-electrically conducting material such asplastic.

Turning to FIGS. 4 and 6, the proximal assembly 19 includes mechanismscapable of moving the insulating and elongated members 14, 16 to variouspositions relative to the needle 12 and relative to each other,including moving the insulating member 14 relative to the needle 12, andmoving the elongated member 16 relative to both the needle 12 and theinsulating member 14. In the preferred embodiment, as shown in FIGS.4-7, one mechanism includes a cage 20 having a proximal end 20 a, adistal end flange 20 b, and a spring 24. The spring 24 has a proximalend 24 a fixed to the housing 21 and a distal end 24 b resting on ormounted to the distal end flange 20 b of the cage 20. The fixed proximalend 24 a of the spring 24 is preferably fixed within notches or recesses21 a (FIGS. 4, 6) defined by the housing 21. The distal end flange 20 bof the cage 20 is preferably disk shaped and wide enough to act as abase against which the distal end 24 b of the spring 24 abuts (See FIGS.3B-3D). In the configuration of the surgical assembly 10 shown in FIGS.4 and 6, which is further discussed below, the distal end flange 20 b ofthe cage 20 is in contact with a horizontal member 22 of the housing 21.

The cage 20 is mounted to the proximal end 14 a of the insulating member14. The mounting can be accomplished by adhering with adhesive theproximal end 14 a of the insulating member 14 to the circumference of acentral hole (not shown) defined in the distal end flange 20 b of thecage 20. Alternatively, the insulating member 14 and cage 20 may beaffixed together mechanically. The cage 20 is movable to upper (FIG. 3A)and lower positions (FIGS. 3B-3D) relative to the housing 21 and needle12. When the cage 20 is in the lower position, the flange portion 20 bis in direct contact with the horizontal member 22 of the housing 21.The horizontal member 22 defines a hole through which the insulatingmember 14 extends, and prevents the cage 20 from moving distally beyondthe lower position toward the sharp distal end 12 b of the needle 12.The spring 24 preferably wraps around the cage 20 and extends downwardfrom the fixed proximal end 24 a to the movable distal end 24 b, whichmoves with the cage 20 along the longitudinal axis 12 c of the needle12. As the cage 20 is moved toward the upper position (FIG. 3A), themovable distal end 24 b of the spring 24 is pushed upward by the distalend 20 b of the cage 20, which compresses the spring 24. The spring 24thus biases the cage 20 toward the lower position (FIGS. 3B-3D, 4)absent any counter acting forces on the cage 20.

The cage 20, spring 24, and insulating member 14 are operably situatedand dimensioned such that when the cage 20 is in the upper position(FIG. 3A), the distal end 14 b of the insulating member 14 is disposedinside of the hollow needle 12, and the sharp distal end 12 b of theneedle 12 is exposed (FIG. 2A). As the cage 20 moves distally toward thelower position (FIGS. 3B-3D), the insulating member 14, whose proximalend 14 a is mounted to the cage 20, is moved distally relative to thehollow needle 12, whereby the distal end 14 b of the insulating member14 may be moved beyond the sharp distal end 12 b of the needle 12 inorder to protect and insulate the sharp distal end 12 b (FIGS. 2B-2D).

In the preferred embodiment, the proximal assembly 19 also includes aplunger 28 mechanically coupled to the proximal end 16 a (FIG. 4) of theelongated member 16. The plunger 28 is connected to a handle 34 that maybe grasped by a user in order to proximally and distally move theplunger 28. The handle 34 connected to the plunger 28 is preferablyidentical or similar to that described in commonly owned U.S. patentapplication Ser. No. 11/685,522. The plunger 28 is longitudinallymovable to proximal, intermediate, and distal positions relative to thehousing 21 as described hereinafter.

As shown in FIGS. 5 and 7, the plunger 28 preferably has projections,hooks, or a flange 30 projecting from a distal end 28 b of the plunger28. As the plunger 28 is moved proximally (away from the distal end 12 bof the needle 12) the hooks 30 of the plunger 28 couple with the cage 20and pull the cage 20 toward the upper position. In the preferredembodiment shown, the cage 20 is hollow so that the plunger 28 iscoaxially movable inside the cage 20. Thus, as shown in FIG. 7, the cage20 may be formed with a small opening 25 at or near its proximal end 20a such that when the hooks 30 of the plunger 28 reach the opening 25,they cannot fit therethrough. The hooks 30 therefore grab onto the rim32 formed inside the cage 20 whereby the cage 20 is pulled by theplunger 28 in a proximal direction relative to the needle 12. As thecage 20 moves toward the upper position (FIG. 3A), the movable distalend 24 b of the spring 24, which is either mechanically coupled to orresting on top of the horizontal distal portion 20 b of the cage 20,moves with the cage 20, thus compressing the spring 24 between the fixedproximal end 24 a and the movable distal end 24 b.

The surgical assembly 10 preferably includes a mechanism for fixing thesurgical assembly 10 in first, second, third, and fourth configurations(shown in FIGS. 3A-3D, which correspond to FIGS. 2A-2D). The mechanismfor fixing the surgical assembly 10 in one of the four configurationsincludes a spring-loaded ball set screw 36 (FIGS. 4 and 6) that ismounted in the housing 21. The set screw 36 is received by holes ordetents 38 a, 38 b, 38 c, and 38 d (FIG. 5) defined by the plunger 28 asthe plunger 28 is moved proximally and distally within the needle 12,which temporarily locks the surgical assembly 10 into one of theconfigurations. The plunger 28 is moved out of a given configuration bypushing or pulling the plunger 28 distally or proximally, therebyapplying enough force to the plunger 28 to overcome the temporary lockcreated by the set screw 36 and a given hole or detent 38 a-d.

In the first configuration (FIGS. 2A, 3A), the surgical assembly 10 isin an armed retracted position with the sharp distal end 12 b of theneedle exposed. In this configuration, the handle 34 and plunger 28 aredisposed in the most proximal position, and the cage 20 is in the upper(most proximal) position, which positions the distal end 14 b of theinsulating member 14 inside the needle 12 such that the sharp distal end12 b of the needle 12 is exposed and ready for insertion into a patient.In addition, as the plunger 28 is in the most proximal position, theresilient wire 18 is also fully retracted and disposed inside of theneedle 12. The set screw 36 is optionally disposed in the most distalhole 38 d (FIG. 5) nearest the hooks 30 of the plunger 28. The plunger28 may also be designed without the hole 38 d such that the firstconfiguration is achieved only so long as a surgeon holds the plunger 28in the most proximal position. For example, a strong enough spring 24may be used such that, without the hole or detent 38 d, if a surgeonreleases the handle 34, the spring 24 automatically transitions thesurgical assembly 10 to the second configuration (discussed below), inwhich the cage 20 is in the lower position and the distal end 14 b ofthe insulating member 14 is disposed beyond the sharp distal end 12 b ofthe needle 12.

If the plunger 28 is manually moved distally from the firstconfiguration, the spring 24, which is compressed, pushes the cage 20distally toward the lower position, whereby the cage 20 and insulatingmember 14 are moved by the spring 24 with the movement of the plunger28. The spring 24 cannot cause a distal displacement of the cage 20greater than that of the plunger 28 if the plunger 28 is held in placebecause the rim 32 (FIG. 5) of the cage 20 will be stopped by the hooks30 of the plunger 20. In other words, if the plunger 28 is stopped aftera small distal displacement from the first configuration (e.g. byholding the handle 34 such that the plunger 28 assumes a position wherethe detents 38 a-d are not engaged by the ball set screw 36), the cage20 will come to rest between the upper and lower positions with thespring 24 still in a compressed configuration but unable to push thecage 20 to the lower position on account of the rim 32 of the cage 20being in contact with the hooks 30 of the plunger 28.

The plunger 28 may be moved distally to arrive at the secondconfiguration (FIGS. 2B, 3B). In the second configuration, the set screw36 is disposed in the hole 38 c (FIG. 5), which places the plunger 28 ina first extended position. In this second configuration, the cage 20 isdisposed in the lower position, the distal end flange 20 b of the cage20 having come up against the horizontal member 22 of the housing 21 asdiscussed above when the set screw 36 snapped into the hole 38 c of theplunger 28. Thus, the insulating member 14 travels with the plunger 28between the first and second configurations, which locates the distalend 14 b of the insulating member 14 beyond the sharp distal end 12 b ofthe needle 12, which protects and insulates the sharp distal end 12. Inaddition, the cauterizing tip 18 b of the resilient wire 18, havingmoved distally as the plunger 28 moved distally, is now disposed beyondthe distal end 12 b of the needle 12, but inside the insulating member14, which electrically insulates the cauterizing tip 18. Thisconfiguration thus allows the surgical assembly 10 to be maneuveredwithin the patient without cutting any tissue with the sharp distal end12 b, and without cauterizing any tissue with the cauterizing tip 18.This second configuration also helps to protect the patient fromaccidental trauma by blocking the sharp distal end 12 b of the needle12. For example, if the needle 12 is inadvertently pushed forward by thesurgeon or another person, the insulating member 14 may prevent thesurgical assembly 10 from puncturing additional tissue or even a vitalorgan. As discussed above, a strong enough spring 24 may be utilized tobias the surgical assembly 10 from the first configuration to the secondconfiguration in the event that the plunger 28 is released therebetween.Such an arrangement may increase the safety of the surgical assembly 10by automatically covering the sharp distal end 12 b of the needle 12when the handle 34 is released.

The plunger 28 may be moved distally to arrive at the thirdconfiguration (FIGS. 2C, 3C). In the third configuration (FIGS. 2C, 3C),the set screw 36 is disposed in the hole 38 b (FIG. 5), which places theplunger 28 in a second extension position. In this third configuration,the distal end 14 b of the insulating member 14 is disposed beyond thesharp distal end 12 b of the needle 12. In addition, the cauterizing tip18 b of the resilient wire 18 is disposed just beyond the distal end 14b of the insulating member 14 along or adjacent the longitudinal axis 12c of the needle 12 because when the plunger was moved from the secondconfiguration to the third configuration, the resilient wire 18 moveddistally while the cage 20 and insulating member 14 remained stationary,the flange 20 b of the cage 20 being unable to move because of thehorizontal member 22 of the housing 21.

The third configuration allows for the electrical activation andoperation of the cauterizing tip 18 while insulating the sharp distalend 12 b of the needle 12. A leaf spring 40 (FIGS. 4 and 8) and bananaplug 42 (FIGS. 4 and 6) are provided to the surgical assembly 10 toelectrify the cauterizing tip 18 b. The banana plug 42 is electronicallycoupled with the leaf spring 40, and is preferably electronicallycoupled to a foot pedal (not shown), which, when depressed, suppliescurrent to the banana plug 42. The leaf spring 40 is positioned suchthat a first end 40 a is movable and biased towards the elongated member16 while a second leaf spring end (not shown) is fixed to the housing 21and/or banana plug 42. The first leaf spring end 40 a of the leaf spring40 rides along the exterior surface 29 of the outer wall of the plunger28 when the plunger is disposed in and between the first (FIG. 3A) andsecond (FIG. 3B) configurations. When the plunger 28 is moved from thesecond configuration toward the third configuration (FIG. 3C), the firstleaf spring end 40 a rides along a tapered groove 44 (FIG. 3B) cut intothe plunger 28, and makes contact with the elongated member 16 when theplunger 28 reaches the third configuration (in which the set screw 36 isdisposed in hole 38 b), at which point the tapered slot extends all theway through the wall of the plunger 28.

When a foot pedal (not shown) is depressed, electrical current travelsup through the banana plug 42, through the leaf spring 40, into and downthe elongated member 16, into and down the resilient wire 18, to thecauterizing tip 18 b. The current and voltage difference between thecauterizing tip 18 b and the ground, which, in the case of monopolarelectro-cauterization, is the patient, generates heat in the cauterizingtip 18 b. As previously discussed, the resilient wire 18 is preferablyinsulated between the proximal end 18 a and the cauterizing tip 18 b,but not at the cauterizing tip 18 b. The resilient wire 18 thus becomesa cauterization device that may be used to cauterize surgical areas tostop internal bleeding and/or to cut through tissue inside the patientin order to destroy and/or remove it.

The plunger 28 may again be moved distally to arrive at the fourthconfiguration (FIGS. 2D, 3D). In the fourth configuration, the set screw36 is disposed in the hole 38 a (FIG. 5), which places the plunger 28 ina third extension position. In this fourth configuration, the distal end14 b of the insulating member 14 is disposed beyond the sharp distal end12 b of the needle 12, and the plunger 28 is fully extended, which fullyextends the resilient wire 18 and disposes the cauterizing tip 18 b evenfurther beyond the distal end 14 b of the insulating member 14. Theresilient wire 18 is preferably resiliently biased toward a bentconfiguration such that the resilient wire 18 bends as it is exposed andis no longer within the needle 12 and/or insulating member 14. As seenin FIGS. 1 and 2D, the bending of the resilient wire 18 situates thecauterizing tip 18 b at a location offset from the longitudinal axis 12c of the needle, and outside the cylindrical projection of the outerwall of the needle 12.

The fourth configuration also allows for the electrical activation andoperation of the cauterizing tip 18 while insulating the sharp distalend 12 b of the needle 12 with the insulating member 14. In thisconfiguration, the distance at which the cauterization tip 18 b isoffset from the longitudinal axis 12 c of the needle 12 is at least aslarge as one half of the outer diameter of the needle 12, and preferablyat least as large as twice the outer diameter of the needle 12. Thepositioning of the cauterizing tip 18 b outside of the peripheralprojection of the needle 12 allows for electrical activation andoperation of the cauterizing tip 18 b and increases the reachable areawithin the patient after the surgical assembly 10 is inserted through asmall incision at a specific location.

Preferably, the cauterizing tip 18 b of the resilient wire 18 iselectrified once it extends beyond the distal ends 12 b, 14 b of theneedle and insulating member 14. At any time, the resilient wire 18 andelongated member 16 may be retracted within the needle 12 by proximallymoving the plunger 28 relative to the needle 12. The surgical assemblycan then be pulled out of the body, leaving only a small puncture markwhich will often heal without a scar.

The surgical assembly 10 can also be moved from the fourth configurationto the third configuration, from the third configuration to the secondconfiguration, and from the second configuration to the firstconfiguration by simply moving the plunger 28 in a proximal direction,which reverses the process described above. When the plunger 28 is movedin a proximal direction from the second configuration to the firstconfiguration, the hooks 30 of the plunger 28 grab onto the upper rim 32of the cage 20 and pull the cage 20 toward the upper position, whichmoves the insulating member 14 proximally to expose the sharp distal end12 b of the needle 12.

The four configurations of the surgical assembly 10 may be used duringlaparoscopic surgery instead of using extra trocars and laparoscopicinstruments. In particular, with the insulating member 14, elongatedmember 16, and resilient wire 18 all disposed inside the needle 12, theneedle 12 is used to puncture the skin, and is advanced into the body(e.g., the abdomen). At a desired location (typically under guidance ofan already inserted scope), the movement of the needle 12 is stopped.The plunger 28 is then distally advanced relative to the needle 12 untilthe distal end 14 b of the insulating member 14 extends past the sharpdistal end 12 b of the needle 12. When the plunger 28 reaches the secondconfiguration, the surgical assembly 10 may be left in place while thesurgeon operates another tool, as this configuration insulates theneedle 12 and acts as a barrier to help prevent injury or trauma to thepatient. The plunger 28 may then be further distally advanced to thethird and fourth configurations, which extend and expose the resilientwire 18 and enable the surgical assembly 10 to be used as an insulatedelectro-cauterization tool. It is noted that because of the smalldiameter of the surgical assembly 10, withdrawal of the needle 12 fromthe abdomen will not cause desufflation, and should not requirestitching to close the wound. It is also noted that because of the smalldiameter of the surgical assembly 10 and the elimination of a trocarport, the surgical assembly 10 can be easily moved in any direction(i.e., it can be easily angled) during surgery. The surgical assembly 10of the invention utilizes a minimum number of parts and may be used toreplace expensive trocar assemblies and laparoscopic instruments.

It will be appreciated by those skilled in the art that the minimallyinvasive surgical assembly 10 can be used for various surgicalprocedures, including but not limited to, tuboplasty, gastric bypass,bowel connection, kidney surgery, appendectomy, menisectomy, discectomy,etc. The minimally invasive surgical assembly 10 of the invention alsohas particularly advantageous uses in neonatal and pediatric surgeries,and may be used on animals or cadavers.

There have been described and illustrated herein several embodiments ofa surgical assembly and methods of its use. While particular embodimentsof the invention have been described, it is not intended that theinvention be limited thereto, as it is intended that the invention be asbroad in scope as the art will allow and that the specification be readlikewise. Thus, while particular materials for making the needle,insulating member, elongated member, and resilient member have beendisclosed, it will be appreciated that other materials may be used aswell. In addition, while particular fixing elements and systems havebeen disclosed for fixing and moving the insulating member and elongatedmember relative to needle, it will be understood that other mechanismscan be used. Further, while the needle, insulating member, and elongatedmember have been shown as being straight, because of their smalldiameter they may be bent together by the user, or one or both may beformed with a bend (arc). Moreover, while particular configurations havebeen disclosed in reference to the relative positions of the needle,insulating member, elongated member, and resilient wire relative to eachother, it will be appreciated that other configurations could be used aswell. In addition, while specific sizes, dimensions, and angles havebeen disclosed for the surgical assembly and its components, it will beappreciated that other dimensions, sizes, and angles may be used. Itwill therefore be appreciated by those skilled in the art that yet othermodifications could be made to the provided invention without deviatingfrom its spirit and scope as claimed.

1. A surgical instrument assembly comprising: a hollow needle having alongitudinal axis, and a sharp distal end; an insulating member operablydisposed within said hollow needle and being movable relative to saidhollow needle, said insulating member having a distal end; a wiremovable through and relative to both said insulating member and saidhollow needle, wherein said wire is retractable within both of saidinsulating member and said hollow needle and extendable beyond both ofsaid distal end of said insulating member and said sharp distal end ofsaid hollow needle, said wire having a distal tip; a housing fixed tosaid hollow needle; and a sub-assembly disposed at least partiallyinside said housing, said sub-assembly being operable to move saidinsulating member relative to said hollow needle and move said wirerelative to said hollow needle and said insulating member, saidsub-assembly including a cage and a plunger, said cage beingmechanically coupled to said insulating member, and said plunger beingmechanically coupled to said wire and movable relative to said cage in adistal direction relative to said hollow needle; wherein said plungerhas engaging means for selectively engaging said cage to move said cageproximally along a portion of said longitudinal axis of said hollowneedle whereby said insulating member is moved proximally relative tosaid hollow needle.
 2. The surgical instrument assembly according toclaim 1, wherein said engaging means comprises projections, hooks, or aflange extending radially relative to said longitudinal axis.
 3. Thesurgical instrument assembly according to claim 1, wherein said cage ismovable along said longitudinal axis from a lower position to an upperposition and vice versa relative to said sharp distal end of said hollowneedle, wherein said plunger is movable along said longitudinal axisfrom a proximal position through a decoupling position to a distalposition relative to said sharp distal end of said hollow needle,wherein, when said plunger is disposed between said proximal positionand said decoupling position, said engaging means of said plunger engagesaid cage, and movement of said plunger causes said insulating memberand said wire to move relative to said hollow needle, and wherein, whensaid plunger is moved between said decoupling position and said distalposition, said wire moves relative to said hollow needle while saidinsulating member is stationary relative to said hollow needle.
 4. Thesurgical instrument assembly according to claim 3, wherein said housingincludes a member substantially perpendicular to said longitudinal axisthat prevents said cage from moving distally beyond said lower position.5. The surgical instrument assembly according to claim 3, wherein saidplunger and said cage are situated such that said cage is disposed insaid upper position when said plunger is disposed in said proximalposition, and said cage is disposed in said lower position when saidplunger is disposed between said decoupling position and said distalposition.
 6. The surgical instrument assembly according to claim 3,further comprising: a spring-loaded set screw mounted to said housing,wherein said spring-loaded set screw is received by at least one detentor hole defined by said plunger to temporarily fix said surgicalinstrument assembly in at least one of said first, second, third, andfourth configurations.
 7. The surgical instrument assembly according toclaim 1, wherein said surgical instrument assembly is configured toassume at least a first configuration and a second configuration,wherein in said first configuration, said wire and said insulatingmember are disposed inside of said hollow needle such that said sharpdistal end of said hollow needle is exposed, and wherein in said secondconfiguration, said insulating member extends parallel to thelongitudinal axis of the hollow needle beyond said sharp distal end ofsaid hollow needle and said wire is completely disposed within saidinsulating member such that the distal tip of said wire is proximal tosaid distal end of said insulating member.
 8. The surgical instrumentassembly according to claim 7, wherein said surgical instrument assemblyis further configured to assume a third configuration and a fourthconfiguration, wherein in said third configuration, said distal tip ofsaid wire extends beyond both said distal end of said insulating memberand said sharp distal end of said hollow needle, and said distal end ofsaid insulating member is disposed beyond said sharp distal end of saidhollow needle such that said sharp distal end is protected, and whereinin said fourth configuration, said sharp distal tip of said wire extendsbeyond both said distal end of said insulating member and said sharpdistal end of said hollow needle, said insulating member extends beyondsaid sharp distal end of said hollow needle in a direction parallel tothe longitudinal axis of said hollow needle, and said distal tip of saidwire is offset from said longitudinal axis of said hollow needle by adistance greater than one half of an outer diameter of said hollowneedle.
 9. The surgical instrument assembly according to claim 8,further comprising: a leaf spring which in said first and secondconfigurations is insulated from said wire, and which in said third andfourth configurations is in electric contact with said wire such thatsaid wire can be electrified to function as a cautery device.
 10. Thesurgical instrument assembly according to claim 1, wherein saidsub-assembly further includes a spring, said spring having one end fixedto said housing and another movable end in contact with said cage,wherein said spring biases both said cage and said insulating member inthe distal direction relative to said housing.
 11. The surgicalinstrument assembly according to claim 1, further comprising: anelongated member extending through said hollow needle and connecting toa proximal end of said wire.
 12. The surgical instrument assemblyaccording to claim 1, wherein said wire is biased toward a bentconfiguration whereby said distal tip moves away from said longitudinalaxis of said hollow needle when said distal tip extends beyond saiddistal end of said insulating member.
 13. The surgical instrumentassembly according to claim 1, wherein an outer diameter of said hollowneedle is 2.2 mm±20%.
 14. A surgical instrument assembly comprising: ahollow needle having a longitudinal axis, and a sharp distal end; aninsulating member operably disposed within said hollow needle and beingmovable relative to said hollow needle, said insulating member having adistal end; a wire movable through and relative to both said insulatingmember and said hollow needle, wherein said wire is retractable withinboth of said insulating member and said hollow needle and extendablebeyond both of said distal end of said insulating member and said sharpdistal end of said hollow needle, said wire having a distal tip; ahousing fixed to said hollow needle; and a sub-assembly disposed atleast partially inside said housing, said sub-assembly being operable tomove said insulating member relative to said hollow needle and move saidwire relative to said hollow needle and said insulating member, saidsub-assembly including a cage, a spring, and a plunger, said cage beingmechanically coupled to said insulating member, said spring having oneend fixed to said housing and another movable end in contact with saidcage, and said plunger being mechanically coupled to said wire andmovable relative to said cage in a distal direction relative to saidhollow needle, wherein said spring biases both said cage and saidinsulating member in the distal direction relative to said housing, andwherein said plunger having engaging means for selectively engaging saidcage to move said cage proximally along a portion of said longitudinalaxis of said hollow needle whereby said insulating member is movedproximally relative to said hollow needle.
 15. The surgical instrumentassembly according to claim 14, wherein said surgical instrumentassembly is configured to assume at least a first configuration and asecond configuration, wherein in said first configuration, said wire andsaid insulating member are disposed inside of said hollow needle suchthat said sharp distal end of said hollow needle is exposed, and whereinin said second configuration, said insulating member extends parallel tothe longitudinal axis of the hollow needle beyond said sharp distal endof said hollow needle and said wire is completely disposed within saidinsulating member such that the distal tip of said wire is proximal tosaid distal end of said insulating member.
 16. The surgical instrumentassembly according to claim 15, wherein said surgical instrumentassembly is further configured to assume a third configuration and afourth configuration, wherein in said third configuration, said distaltip of said wire extends beyond both said distal end of said insulatingmember and said sharp distal end of said hollow needle, and said distalend of said insulating member is disposed beyond said sharp distal endof said hollow needle such that said sharp distal end is protected, andwherein in said fourth configuration, said sharp distal tip of said wireextends beyond both said distal end of said insulating member and saidsharp distal end of said hollow needle, said insulating member extendsbeyond said sharp distal end of said hollow needle in a directionparallel to the longitudinal axis of said hollow needle, and said distaltip of said wire is offset from said longitudinal axis of said hollowneedle by a distance greater than one half of an outer diameter of saidhollow needle.
 17. The surgical instrument assembly according to claim14, further comprising: an elongated member extending through saidhollow needle and connecting to a proximal end of said wire.
 18. Thesurgical instrument assembly according to claim 14, wherein said wire isbiased toward a bent configuration whereby said distal tip moves awayfrom said longitudinal axis of said hollow needle when said distal tipextends beyond said distal end of said insulating member.
 19. Thesurgical instrument assembly according to claim 14, wherein an outerdiameter of said hollow needle is 2.2 mm±20%.